JPH11146672A - Driver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driver which is so arranged as not to drag the cable connected to each electrode of an electromechanical converter element. SOLUTION: A first fixing frictional member 15 being a conductive member is fixed to a base 14 consisting of an insulator, and in parallel with this, a second fixing frictional member 16 being a conductive member is supported through a support spring 18. Each electrode of a drive pulse generating circuit 12 and the fixing frictional members 15 and 16 are connected with each other, respectively A drive unit 20, where a piezoelectric element 22 and a drive shaft 26 small in mass are coupled in series to a mover 24 large in mass, is arranged between a pair of fixing frictional members 15 and 16, and they are frictionally coupled with each other, holding the drive shaft 26. The drive shaft 26 consists of conductors coupled with each other on both sides of an insulator, and each conductor contacts with the fixing frictional members 15 and 16 for current application. Each electrode of a piezoelectric element 22 and each conductor of the drive shaft 26 are connected with each other by a short cable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a driving device,
More specifically, the present invention relates to a driving device using an electromechanical conversion element such as a piezoelectric element, for example, an XY driving table, a photographic lens of a camera, a projection lens of an overhead projector,
The present invention relates to a driving device suitable for precision driving, such as a lens of binoculars, a moving stage of a microscope, and a probe of a scanning tunneling electron microscope.

[0002]

2. Description of the Related Art Heretofore, the present applicant has proposed various driving devices which achieve high resolution on the order of sub-μm using a piezoelectric linear actuator instead of a stepping motor.

For example, as an example, a driving device 100 shown in a perspective view of FIG. 1 includes a first fixed friction member 115 fixed to a base 114 and a first fixed friction member 11.
5 are arranged in parallel with the base 11 via a support spring 118.
4 between the second fixed friction member 116 supported on
The drive unit 120 is disposed, and the drive shaft 125 of the drive unit 120, that is, the drive friction member 125 is sandwiched between the fixed friction members 115 and 116 and frictionally coupled.

More specifically, the drive unit 120 is connected to a stage or the like (not shown) on which components are mounted, and has a relatively large mass of a moving body 124, a piezoelectric element 122, and a drive shaft 125 having a relatively small mass. Consists of Piezoelectric element 122
Is expanded and contracted by applying a drive pulse from the drive circuit 112. A moving body 124 is fixedly connected to one end face of the piezoelectric element 122 in the expansion and contraction direction, and one shaft end face of a drive shaft 125 is fixedly connected to the other end face. The drive shaft 125 is
The movable body 122 is movable in the expansion and contraction direction of the piezoelectric element 124.
It is supported by.

By the way, each electrode of the piezoelectric element 122 and each electrode of the drive pulse generating circuit 112 are connected to the electric wire 11 respectively.
3a and 113b, and a drive pulse is supplied to the piezoelectric element 122. Electric wires 113a, 11
3b needs to have a length equal to or greater than the moving amount of the drive unit 120.

However, the use of the long electric wires 113a and 113b requires a space for the processing, and requires a device for reducing the size of the mechanism. In addition, since the wires 113a and 113b are also dragged by the movement of the drive unit 120, the wires 113a and 113b are moved during the movement.
13b is another part, for example, the fixed friction members 115, 11
6 must be configured so as not to cause a problem such as contact with the resistor 6, which becomes a resistance and lowers drive performance or breaks.

[0007]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a driving device which does not drag an electric wire connected to each electrode of an electromechanical transducer.

[0008]

In order to solve the above technical problems, the present invention provides the following drive device.

The driving device includes a driving pulse generating means for generating a driving pulse, an electromechanical conversion element which expands and contracts by applying the driving pulse, and a moving body fixedly connected to one end of the electromechanical conversion element in the expansion and contraction direction. A driving friction member fixedly connected to the other end of the electromechanical conversion element in the expansion / contraction direction, and a stop friction member frictionally connected to the driving friction member. The driving pulse generating means expands and contracts the electromechanical conversion element. The driving friction member is driven to move the moving body in a predetermined direction. The drive pulse is supplied to the electromechanical transducer via the stopping friction member.

In the above construction, slippage occurs between the stopping friction member and the driving friction member that are frictionally coupled to each other, and the relative distance between the stopping friction member and the driving friction member varies when the electromechanical transducer expands and contracts. The drive pulse generation means expands and contracts the electromechanical conversion element so that the movement amount differs. Accordingly, the driving friction member moves in a predetermined direction while sliding with respect to the stopping friction member, and the moving body also moves in a predetermined direction.
Even when the electromechanical transducer is extended and contracted, slippage of different sizes occurs between the stopping friction member and the driving friction member, or when the electromechanical transducer is extended or contracted. Slip may occur in only one of them.

In the above configuration, since the driving friction member moves along the stopping friction member, the electromechanical conversion element is
It moves along the stopping friction member. Since the electromechanical transducer is close to the stopping friction member, it is possible to supply a drive pulse to the electromechanical transducer at a short distance from the stopping friction member to the electromechanical transducer.

Therefore, it is possible to prevent the electric wires connected to the respective electrodes of the electromechanical transducer from being dragged.

Preferably, at least one first contact means fixed to the stopping friction member substantially along a driving range of the driving friction member and electrically connected to the driving pulse generating means, A second electrode disposed in the vicinity of the electromechanical transducer, electrically connected to the electromechanical transducer, and slidably contacting the first contact means;
Contact means.

In the above configuration, since the second contact means slides on the first contact means, the second contact means and the first contact means are electrically connected. Therefore, the drive pulse is transmitted to the electromechanical transducer via the drive pulse generating means, the first contact means provided on the stopping friction member, and the second contact means slidably contacting the first contact means. Since the second contact means may be shorter than the driving range of the driving friction member, it is possible to prevent the electric wire connected to the electrode of the electromechanical transducer from being dragged. One electrode of the drive pulse generating means and the electromechanical transducer is appropriately grounded, for example, to the apparatus main body, and only the other electrode is the first and second electrodes.
Or the first and second electrodes may be electrically connected to each other.
May be electrically connected by the contact means.

[0015] Preferably, the driving friction member includes two or more conductive contacts insulated from each other and electrically connected to the respective electrodes of the electromechanical transducer. The stopping friction member includes a conductive electrode portion that is insulated from each other, slidably contacts each of the contact portions of the driving friction member, and is electrically connected to the driving pulse generating means.

In the above arrangement, the contact between the contact portion and the electrode portion is conducted by the sliding contact between the contact portion as the first contact portion and the electrode portion as the second contact portion, and the drive pulse is transmitted. Will be done. Even if the contact portion and the electrode portion also serve as a frictional coupling portion between the driving friction member and the stopping friction member,
Alternatively, they may be provided separately.

Preferably, the stopping friction member is a pair of conductive members which are insulated from each other and electrically connected to the respective electrodes of the driving pulse generating means. The driving friction member has a pair of conductors coupled to both sides of the insulator. Each of the conductors is electrically connected to each of the electrodes of the electromechanical transducer, and is frictionally coupled to each of the conductive members of the stopping friction member.

According to the above configuration, each conductive member of the stopping friction member and each conductor of the driving friction member are frictionally coupled with each other, and are brought into contact with each other to conduct, thereby transmitting a driving pulse.
The contact portion and the electrode portion for transmitting the drive pulse do not have to be provided separately from the frictional coupling portion between the drive friction member and the stop friction member, and the configuration is simplified.

Preferably, the stopping friction member is a pair of conductive members which are insulated from each other and are electrically connected to the respective electrodes of the driving pulse generating means. The driving friction member has an insulating main body and two conductive layers covering the surface of the main body. The conductive layers are separated from each other and electrically connected to the electrodes of the electromechanical transducer, respectively, and are frictionally coupled to the conductive members of the stopping friction member.

According to the above construction, each conductive member of the stopping friction member and each conductive layer of the driving friction member are frictionally coupled with each other and are brought into contact with each other to conduct, thereby transmitting a driving pulse.
The contact portion and the electrode portion for transmitting the drive pulse do not have to be provided separately from the frictional coupling portion between the drive friction member and the stop friction member, and the configuration is simplified.

Preferably, the stopping friction member is a pair of conductive members which are insulated from each other and electrically connected to the respective electrodes of the driving pulse generating means. The electromechanical transducer further includes a pair of conductive contact members that are insulated from each other, electrically connected to the respective electrodes of the electromechanical transducer, and slidably contact the conductive members of the stopping friction member.

According to the above construction, each of the conductive members of the stopping friction member and the conductive layer of the driving friction member are friction-coupled with each other, and the contact member is brought into contact with each of the conductive members of the stopping friction member so as to be electrically connected to each other. The pulse is transmitted to the electromechanical transducer. The friction coupling between the driving friction member and the stopping friction member and the sliding contact between each conductive member of the stopping friction member and the contact member generally have different optimum conditions. Can be configured.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a driving device according to the present invention will be described with reference to FIGS.

First, the driving device 10 according to the first embodiment will be described with reference to FIGS.

As shown in the overall perspective view of FIG. 2, the drive unit 10 according to the first embodiment generally has a drive unit 20 sandwiched above a base 14 by a pair of fixed friction members 15 and 16. Become.

More specifically, the base member 14 is an insulator. The pair of fixed friction members (stop friction members) 15 and 16 are conductive members, and are electrically connected to the respective electrodes of the drive pulse generation circuit 12 by electric wires 13a and 13b, respectively. One of the first fixed friction members 15 is
Is directly fixed to the upper surface 14s of the first member. The other second fixed friction member 16 is arranged in parallel along the first fixed friction member 15, and is elastically supported in a state of floating above the base 14 via a pair of support springs 18. A fixed space is formed between the fixed friction members 15 and 16. The support spring 18 has high rigidity in the longitudinal direction of the second fixed friction member 16, that is, the moving direction of the drive unit 20, and has a moderate elasticity in the direction perpendicular to the moving direction. The first fixed friction member 15 is the second fixed friction member 16
15s is a plane 15s. The surface 16 where the second fixed friction member 16 faces the first fixed friction member 15
s is a V-groove surface 16s having a V-shaped cross section extending along the surface 15s of the opposing first fixed friction member 15. This V
A main body 26s of a drive shaft 26 of the drive unit 20, which will be described in detail later, is engaged with the groove surface 16s, and the drive shaft 26 is urged by the first fixed friction member 15. In other words, the drive unit 20 includes the pair of fixed friction members 15, 1
6, the main body 26 s of the drive shaft 26 is sandwiched between the flat surface 15 s of the first fixed friction member 15 and the V-groove surface 16 s of the second fixed friction member 16, and above the base 12. It is held in a floating state.

The drive unit 20 includes a piezoelectric element 22, a moving body 24, and a drive shaft 26.

The moving body 24 has a substantially columnar main body, and screw holes 24a, 24 for mounting a driven member (not shown), for example, a lens or a stage, on the upper surface thereof.
b is provided. The moving body 24 has two concave portions 24 s and 24 t cut out from the upper surface side, and the piezoelectric element 22 is housed in one concave portion 24 s and the other concave portion 24
At t, the drive shaft 26 is housed.

The piezoelectric element 22 is a kind of electromechanical transducer, and is formed by stacking a plurality of piezoelectric plates whose volume changes when a voltage is applied, and expands and contracts in the stacking direction by a change in the applied voltage. Has become. One end face of the piezoelectric element 22 in the stacking direction is bonded and fixed to a face opposite to the other recess 24t.

The drive shaft 26 is a drive friction member having a shape in which shaft portions 26t protrude on both sides along the central axis of the cylindrical main body portion 26s. The mass of the drive shaft 26 is
4 less than the mass. The drive shaft 26 has its shaft portion 26t
Are respectively inserted into through holes provided on both sides of the other concave portion 24t of the moving body 24, and are slidably supported in the axial direction.
One shaft end face of the drive shaft 26 is bonded and fixed to the other end face of the piezoelectric element 22 in the stacking direction. Main body 2 of drive shaft 26
The outer peripheral surface of 6 s protrudes outside the side surfaces 24 c on both sides of the moving body 24, and is friction-coupled between the surfaces 15 s and 16 s of the pair of fixed friction members 15 and 16.

As shown in the exploded perspective view of FIG. 3, the drive shaft 26 has a sandwich structure in which a pair of conductors 26a and 26b are adhered to both sides of an insulator 26c disposed at the center. Each conductor 26a, 26b of the drive shaft 26
Are arrows 72a and 72b in the exploded perspective view of the main part of FIG.
As shown by, they are electrically connected to the respective electrodes of the piezoelectric element 22 by electric wires 23a and 23b, respectively. Also,
As shown by arrows 70a and 70b, the conductors 26a and 26b are frictionally coupled to the flat surface 15s of the first fixed friction member 15 and the V-groove surface 16s of the second fixed friction member 16, respectively. It is supposed to.

That is, as shown in FIG.
2, the electric wires 13a, 1
3b, conductors 2 of fixed friction members 15, 16 and drive shaft 26
Voltage is applied via 6a, 26b and electric wires 23a, 23b. Electric wires 23a and 23b connected to the piezoelectric element 22
Is simply connected to the conductors 26a, 26b of the drive shaft 26, is short, and moves at both ends together with the drive unit 20. Therefore, the wires 23a and 23b are not dragged.

The driving device 10 configured as described above
By applying a pulse voltage having an appropriate waveform such as a sawtooth shape or a full-wave rectified wave shape to the piezoelectric element 22,
In addition, the driven member can be moved along the fixed friction members 15 and 16. For example, the speed at which the piezoelectric element 22 expands and the speed at which the piezoelectric element 22 contracts are different, and a slip occurs between the drive shaft 26 and the fixed friction members 15 and 16 when the piezoelectric element 22 expands or contracts. On the other hand, the moving body 24 and the driven member are fixed to the fixed friction member 15, so that no slip occurs, or in the opposite direction, the size of which differs when the piezoelectric element 22 expands and contracts. 16 along a predetermined direction.

Next, a driving device 10a according to a second embodiment will be described with reference to FIGS. The drive device 10a according to the second embodiment differs from the drive device 10 according to the first embodiment in the configuration of the drive shaft 27 of the drive unit 20, but the other configurations are the same. Hereinafter, the differences will be mainly described.

As shown in the perspective view of FIG. 5, the drive shaft 27 has a structure in which two conductive layers 27a and 27b cover the surface of the insulating main body 27c in a range of about 180 degrees. Each conductive layer 27a, 27b is insulated from each other. The conductive layers 27a and 27b are electrically connected to the respective electrodes of the piezoelectric element 22 by electric wires 23a and 23b, respectively, as shown by arrows 82a and 82b in an exploded perspective view of the main part of FIG. Further, each conductive layer 27a, 2
7b, as indicated by arrows 80a and 80b, frictionally couples to the flat surface 15s of the first fixed friction member 15 and the V-groove surface 16s of the second fixed friction member 16, respectively, and comes into contact with and conducts. ing.

That is, as shown in FIG.
From the drive pulse generation circuit 12, the electric wires 13a, 13
b, fixed friction members 15, 16 and conductive layer 27 of drive shaft 27
a, 27b and a voltage is applied through the electric wires 23a, 23b. The electric wires 23a and 23b connected to the piezoelectric element 22 are connected to the conductive layers 27a and 27b of the drive shaft 27, and are short and both ends move together with the drive unit, so that they are not dragged.

Next, a driving device 10b according to a third embodiment will be described with reference to FIGS.

The driving device 10b of the third embodiment, as shown in the plan view of FIG. 7, generally has a driving friction member 28 of a driving unit sandwiched between a pair of fixed friction members 30 and 32. Become.

More specifically, a pair of fixed friction members 30, 32
Are conductive members, insulated from each other, and
3b is electrically connected to each electrode of the drive pulse generation circuit 12 respectively. One of the first fixed friction members 30 is provided with a pair of support portions 34, and supports the other second fixed friction member 32 in parallel along the first fixed friction member 30. . A biasing spring 36 is disposed on each of the end portions of the pair of support portions 34 so as to bias the second fixed friction member 32 toward the first fixed friction member 30.

The driving unit is constituted separately from the piezoelectric element 22, the moving body 24, the driving friction member 28, and the driving friction member, and has a pair of contact members 29a,
29b.

One end face of the piezoelectric element 22 in the stacking direction is provided with an end face of the moving body 24, and the other end face is provided with a driving friction member 28.
Are fixed by bonding, and a moving body 24 and a driving friction member 28 are arranged on both sides of the piezoelectric element 22.

The driving friction member 28 is made of an insulating material.
Since the width is larger than the width of the piezoelectric element 22 and the width of the moving member 24, the outer peripheral surface of the driving friction member 28 is sandwiched between the opposing surfaces of the pair of fixed friction members 30, 32 and frictionally coupled. .

Each of the pair of contact members 29a and 29b is made of a conductive member, and one end thereof is supported near the piezoelectric element 22. The contact members 29a and 29b extend in parallel with the fixed friction members 30 and 32 through the side of the driving friction member 28, and the other ends are bent to opposite sides. The one ends of the pair of contact members 29a and 29b are electrically connected to the respective electrodes of the piezoelectric element 22 by electric wires 23a and 23b, respectively, as shown by arrows 92a and 92b in an exploded perspective view of the main part of FIG. . Further, a pair of contact members 29a,
29b are connected to the arrows 90a, 90 in FIGS.
0b, the pair of fixed friction members 30 and 32
Each of them is frictionally connected and comes into contact with and conducts.

In other words, the piezoelectric element 22 receives the electric wires 13 a and 13 b and the fixed friction member 3 from the drive pulse generation circuit 12.
0, 32, contact members 29a, 29b, electric wires 23a, 23
A voltage is applied via b. The electric wires 23a and 23b connected to the piezoelectric element 22 are connected to the contact members 29a and 29b, are short, and both ends move together with the drive unit, so that they are not dragged.

The driving device 10 of each embodiment described above,
10a and 10b can be made small by eliminating the operation of changing the distance between both ends of the electric wire when moving, and can prevent the drive performance from deteriorating and prevent the electric wire from being damaged. In each of the embodiments, the stopping friction member is constituted by a fixed friction member fixed to the base member, but may not be completely fixed but may be movable, and substantially stops to drive the driving friction member. Anything that moves relatively can be used.

The present invention is not limited to the above embodiments, but can be implemented in various other modes.

[Brief description of the drawings]

FIG. 1 is a perspective view of a conventional driving device.

FIG. 2 is a perspective view of the driving device according to the first embodiment of the present invention.

FIG. 3 is an exploded perspective view of a drive shaft of the drive device of FIG.

FIG. 4 is an exploded perspective view of a main part of the drive device of FIG. 2;

FIG. 5 is a perspective view of a drive shaft of a drive device according to a second embodiment of the present invention.

FIG. 6 is an exploded perspective view of a main part of a driving device according to a second embodiment of the present invention.

FIG. 7 is a plan view of a driving device according to a third embodiment of the present invention.

8 is an exploded perspective view of a main part of the drive device of FIG. 7;

[Explanation of symbols]

10, 10a, 10b Driving device 12 Pulse generating circuit (driving pulse generating means) 13a, 13b Electric wire 14 Base 14s Upper surface 15 First fixed friction member (First contacting means, electrode portion, conductive member) 15s Flat surface 16th 2 fixed friction member (first contact means, electrode portion, conductive member) 16s V-groove surface 18 support spring 20 drive unit 22 piezoelectric element (electromechanical conversion element) 23a, 23b electric wire 24 moving body 24a, 24b screw hole 24c Side surface 24s, 24t recess 26 Drive shaft (drive friction member) 26a, 26b Conductor (second contact means, contact portion) 26c Insulator 26s Main body 26t Shaft 27 Drive shaft (drive friction member) 27a, 27b Conduction Layer (second contact means, contact portion) 27c Body portion 28 Drive friction member 29a, 29b Contact Material (second contact means) 30 First fixed friction member (first contact means, electrode portion, conductive member) 32 Second fixed friction member (first contact means, electrode portion, conductive member) 34 support part 36 urging spring 70a, 70b-92a, 92b arrow

Claims (6)

[Claims] A driving pulse generating means for generating a driving pulse; an electromechanical transducer that expands and contracts by receiving the driving pulse; a moving body fixedly connected to one end of the electromechanical transducer in the direction of expansion and contraction; A driving friction member fixedly connected to the other end of the electromechanical conversion element in the expansion / contraction direction; and a stop friction member frictionally connected to the driving friction member. The electromechanical conversion element is expanded and contracted by the driving pulse generating means. A driving device for driving a driving friction member and moving the moving body in a predetermined direction, wherein the driving pulse is supplied to the electromechanical conversion element via the stopping friction member. apparatus. 2. The at least one first contact means fixedly mounted on the stop friction member substantially along a drive range of the drive friction member and electrically connected to the drive pulse generating means. 2. A device according to claim 1, further comprising second contact means disposed near the mechanical conversion element, electrically connected to the electromechanical conversion element, and slidably contacting the first contact means. The driving device as described. 3. The driving friction member includes two or more conductive contacts that are insulated from each other and electrically connected to respective electrodes of the electromechanical transducer, and the stopping friction members are insulated from each other. 2. The drive device according to claim 1, further comprising a conductive electrode portion which is in contact with each of said contact portions of said drive friction member and is electrically connected to said drive pulse generation means. 4. The stopping friction member is a pair of conductive members that are insulated from each other and are electrically connected to the respective electrodes of the driving pulse generating means. The driving friction member includes a pair of conductors. Each of the conductors is electrically connected to each of the electrodes of the electromechanical transducer, and each of the conductors is frictionally coupled to each of the conductive members of the stopping friction member. The drive device according to claim 1, wherein: 5. The stopping friction member is a pair of conductive members insulated from each other and electrically connected to each electrode of the driving pulse generating means, respectively. The driving friction member is an insulating main body. And two conductive layers that cover the surface of the main body. The conductive layers are separated from each other and electrically connected to the respective electrodes of the electromechanical transducer, respectively. The drive device according to claim 1, wherein each of the conductive members is frictionally coupled to each of the conductive members. 6. The stopping friction member is a pair of conductive members insulated from each other and electrically connected to each electrode of the drive pulse generating means, respectively. 3. The battery according to claim 1, further comprising a pair of conductive contact members electrically connected to the respective electrodes and slidingly contacting the respective conductive members of the stopping friction member.
The driving device as described.